1. Field of the Invention
This invention relates to tube benders and in particular to manually operable tube benders wherein a forming member is swung about a form wheel so as to forcibly urge a tube into a peripheral arcuate groove of the form wheel to effect a desired bend therein.
2. Description of the Background Art
Manually operable tube benders having a forming member mounted to swing about a bend axis of a forming wheel are well known in the art. Illustratively, in U.S. Pat. No. 2,796,785 of Howard L. Philippe, a manually operable tube bender is shown to have a forming member swingably mounted to the form wheel by means of a link. The forming member comprises a shoe having a groove engaging the outer surface of the tube to be bent and defining the force transfer surface between the shoe and tube. The shoe is pivotally connected to the link by a pivot having a fixed radial distance from the pivot of the link to the form wheel. The form wheel groove has a U-shaped configuration and the groove of the shoe has an arcuate extent of less than 180.degree. for limiting undesirable flattening deformation of the tube in the bending operation.
Leonard J. Kowal, in U.S. Pat. No. 2,887,917, shows a tube bender having a bending shoe swingably mounted to the mandrel with the mandrel having an improved scale means thereon for use in indicating the extent of the bend produced.
In U.S. Pat. No. 3,926,028 of Leonard J. Kowal, another form of manually operable tube bender is illustrated.
In U.S. Pat. No. 3,750,447 of Leonard J. Kowal et al, still another form of manually operable tube bender having a shoe member swingably mounted to the mandrel is disclosed in combination with a novel tube-retaining hook structure.